Drivers in vehicles are often exposed to a lot of distracting and annoying noise. Such subsequently called “unwanted” noise can have multiple negative effects on drivers. The noise may annoy a driver and it may even dangerously decrease a driver's concentration.
Active noise control is based on the phenomenon of “destructive interference”, in which a 180°-phase-shifted anti-noise signal is superimposed on the noise signal so that the noise is decreased significantly. Typically, one or more microphones detect the incoming noise, while a computer calculates a corresponding anti-noise signal which is emitted by one or more speakers to cancel out the incoming noise.
Noise cancellation inside a vehicle cannot be done inside a large volume, i.e. the volume in which the noise is cancelled is small. This poses a problem for ordinary systems, since the area of most effective cancellation might not cover the driver's ears, and hence the noise cancellation is not perceived by the driver. In addition, for immersive audio rendering systems, in particular for systems that make use of binaural cancellation, the sweet spot is very small and therefore such systems cannot be used in a generic way inside the vehicle.